Batches are used to group marks for nesting. You can assign marks to a batch either when you import a preliminary listing or during the prelim or detailed nesting process. You can only nest one batch at a time. Some reports are on a per batch basis.
Using batches may help to avoid user errors when nesting, thus preventing the need to purchase extra material, and reducing wastage. These points are best explained by taking an example.
You import a preliminary listing for a contract that has two phases, Phase 1 and Phase 2. When you continue on to prelim nesting, you decide to assign all of the marks in Phase 1 to a batch called Batch 1, and all of the marks in Phase 2 to a batch called Batch 2. The result of the prelim nest is described below.
For Phase 1:
The following lengths of steel are to be fabricated:
7 x 6000mm
For this, you are going to purchase the following standard lengths of steel:
2 lengths of 12 500mm (to make 4 of the 6000mm lengths)
1 length of 18 500mm (to make 3 of the 6000mm lengths)
For Phase 2:
The following lengths of steel are to be fabricated:
1 x 18 000mm
1 x 24 000mm
For this, you are going to purchase the following standard lengths of steel:
1 length of 18 500mm (to make the 18 000mm length)
1 length of 24 500mm (to make the 24 000mm length)
You go ahead and purchase the standard lengths of steel. Some time later, when your client's plans are finalised, you import a detailed listing and continue on to detailed nesting, where you have the following options for selecting material to use:
§ Allocated to this contract
§ Allocated to this batch
§ Match Prelim Mark Allocations
If you select Match Prelim Mark Allocations or Allocated to this batch, the lengths of steel that are used to fabricate the required lengths are those specified in prelim nesting as described above. Pitfalls my unwittingly occur, however, if you select Allocated to this contract. Take the following situation:
For Phase 1:
The following lengths of steel are to be fabricated:
7 x 6000mm
You previously ordered the following standard lengths, which are now in your inventory:
2 lengths of 12 500mm
2 lengths of 18 500mm
1 length of 24 500mm
You decide to use:
1 length of 18 500mm (to make 3 of the 6000mm lengths)
1 length of 24 500mm (to make 4 of the 6000mm lengths)
This leaves you with the following standard lengths:
2 lengths of 12 500mm
1 length of 18 500mm
When you come to nest the marks for Phase 2, you have enough material to make the 18 000mm length. However, you used the only 24 500mm bar for Phase 1, so you have to purchase another 24 500mm standard length to make the required 24 000mm bar. You also have 2 lengths of 12 500mm unused in inventory.
This example demonstrates how you can optimise the way in which you use material by nesting and ordering on a per batch basis.